1. Field of the Invention
The invention is a soft cranberry, and undersize cranberry separator and method; the invention relates to machines for separating hard, marketable cranberries, from soft and undersize cranberries; separation is based on the greater crush resistance of hard, marketable cranberries.
2. Related Art
Prior art cranberry sorting devices, separate soft cranberries from hard cranberries, based on the resilience of cranberries. That is, hard cranberries bounce, soft cranberries do not bounce.
In prior art, cranberries, to be sorted, are dropped onto a hard surface. The hard surface is mounted at an angle to the direction of fall of the cranberries.
Hard marketable cranberries bounce off the hard, angled surface, into a marketable cranberry collector.
Spoiled or bruised cranberries are soft. Spoiled or bruised cranberries, impact the hard angled surface, and slide down the angled surface, into a rejected cranberry collector.
Repeated bouncing of cranberries on angled surfaces, is used to separate marketable cranberries from spoiled cranberries.
The sorting devices that rely on bouncing, to separate cranberries, clog. The surfaces clog because some soft cranberries are so soft, as to be mush. Mushy, soft cranberries stick to the angled surface.
To bounce from the angled surface, hard marketable cranberries have to land on a clean, hard surface.
The bouncing, sorting devices are based on a premise that cranberries are round and will bounce predictably.
Cranberries are not round. When the cranberries bounce, they may not bounce to the sorting area.
If a cranberry has a small soft spot, the cranberry is not marketable. A cranberry may be repeatedly bounced. If the cranberry is not bounced on the soft spot, it will be passed as a marketable cranberry. Hand sorting is necessary to remove cranberries that have passed through the bounce sorter, to sort out cranberries with soft spots.
The invention, a soft cranberry sorter, uses a different concept to separate soft cranberries from hard marketable cranberries.
Cranberries, to be sorted, are loaded into a hopper. From the hopper, the cranberries are fed into a transport conveyor.
The transport conveyor is comprised of two sets of rollers. One set mounted above the other set. The cranberries pass between soft foam upper rollers, and lower finned rollers, from load end to discharge end.
As the cranberries are transported, the cranberries are repeatedly tested to determine if soft spots exist. If a soft spot exists, the cranberry is forced between the fins of transport rollers, and stripped out by a stripper comb.
The cranberry is rolled, while suspended between two fins, of a hard finned transport roller. Force is applied to the cranberry, by a sponge roller, as the cranberry is rolled between two fins.
If any part of the cranberry, rolled between the two fins, while pressure is put on the cranberry, is soft, as soft is defined by the crush resistance of a cranberry, the cranberry will be forced between the fins.
By applying force, by means of a group of soft sponge rollers, the defective cranberry is urged between the fins of a hard transport roller, without the defective cranberry being crushed.
The device is designed to sort defective cranberries without crushing defective cranberries. Crushing the defective cranberries releases cranberry juice, which contaminates the marketable cranberries, and accelerates deterioration of the sorted cranberries.
The number of finned rollers determines the number of times each cranberry is tested, as each cranberry passes over a finned roller.
Applicant's device sorts cranberries, based on crush resistance of marketable cranberries. Laboratory tests were used, to determine the resistance to crushing, of what was defined as a marketable cranberry. Marketable cranberries are more resistent to crushing than are soft, and therefore, non-marketable cranberries.
Applicant's device is specifically designed to overcome the machine clogging property of severely deteriorated mushy cranberries.
Severely deteriorated mushy cranberries, stick to any surface that they touch.
Applicant strips the defective cranberries from the finned transport rollers, by a closely fitted, stationary stripper comb, mounted between adjacent fins. The teeth of the stripper comb extend upwardly into the area between the fins.
A prior art device, using elasticity of cranberries, to separate cranberries is U.S. Pat. No. 1,339,077. That device forced good cranberries into apertures on a roller. The good cranberries were stripped out of the apertures. A problem with a device using apertures to separate out marketable cranberries, is that the apertures clog with the sticky, mushy, severely deteriorated cranberries.
Another approach to sorting cranberries, is the device shown in U.S. Pat. No. 1,700,302. In that device, conveyors transport cranberries up to diagonal barriers. Solid cranberries slide along the conveyor surface. Soft cranberries are crushed, and forced under the diagonal barriers.